1. Field
The present application relates to a transforming device, an electronic apparatus and a power supply system including such a transforming device and an electronic apparatus.
2. Description of Related Art
An electronic apparatus such as a notebook personal computer can operate with electric power supplied from a built-in battery or electric power supplied from a commercial power source via an AC adaptor. An AC adaptor is an apparatus that transforms a voltage (for example, 100 V) of a commercial power source to a voltage (for example, 16 V) suitable for an electronic apparatus such as a notebook personal computer.
The AC adaptor has an input terminal connectable to a commercial power source and an output terminal connectable to an input terminal provided to an electronic apparatus such as a notebook personal computer. The shape of the output terminals may vary among electronic apparatuses or may have a technical specification that is common among electronic apparatuses of different types. Even when the shapes of the output terminals are of a common technical specification among electronic apparatuses of different types, the rated power or the like may be different between the AC adaptor and the electronic apparatus. If an AC adaptor that has a different rating is connected to an electronic apparatus, the electronic apparatus may not operate normally or the electronic apparatus and/or the AC adaptor may break down. It is preferable therefore that the AC adaptor is used exclusively for a corresponding electronic apparatus.
As described above, for the purpose of preventing misconnection of the AC adaptor, it is possible to provide a means for identifying the type of the AC adaptor connected to the electronic apparatus side. In general, an output terminal of an AC adaptor includes a power source terminal and a ground terminal. By further providing the AC adaptor with an identification terminal and further providing the electronic apparatus with a terminal for AC adaptor identification, the type of AC adaptor can be identified at the electronic apparatus.
JP H05-83864 A discloses a power source device that includes a voltage detection terminal for detecting the voltage of a connected AC adaptor and that detects the terminal voltage at the voltage detection terminal so as to decide the type of the connected AC adaptor.
However, since the structure disclosed by JP H05-83864 A includes exclusive terminals at the terminals of the AC adaptor and of the electronic apparatus so as to decide the type of the AC adaptor, it is necessary to modify the shapes of the output terminal of the AC adaptor and the input terminal of the electronic apparatus. In other words, a structure of identifying the type of AC adaptor cannot be provided without modifying the shapes of the output terminal of the AC adaptor and/or the input terminal of the electronic apparatus.